Rinjani is a challenging trek but Hajar provides the best circumstances to conquer it and enjoy your time while doing it! I've had a wonderful tour with the friendliest and funniest porters and guides I could have hoped for. We also had a nice and supportive group (only 7 people so not too big). Hajar probably gives you the best price considering his service that includes pick up and drop off and a night at the camp in Senaru prior to the trek. He's very quick with communication (via telephone and email) as well.